Machine tooth



40 Model.)

L. CARRIER.

THRASHING MACHINE TOOTH.

No. 252,426. Patented Jan. 17,1882.

F'EI 3| WITNESSEE. INVENTCIRL 424 Q; 4 swam UNITED STATES,

PATENT OFFICE:

LUOIUS CARRIER, OF PROVIDENCE, RHODE ISLAND.

TH RASHING-M ACHINE TOOTH.

SPECIFICATION forming part of Letters Patent No. 252,426, dated January 17, 1882.

' Application filed June 13, 1881. (No model.)

To all whom it may concern.-

Be it known that I, LUOIUS CARRIER, of the city and county of Providence, and State of Rhode Island, have invented a new and useful Improvement in Thrashing-lllachine Teeth; and I hereby declare that the following is a full, clear, and exact description of the same, reference being bad to the accompanying drawings, forming part of this specification.

This invention has reference to an improvement in the teeth or heaters projecting both from the cylinders of thrashing-machines and from the abutmen ts or concaves.

Figure 1 is a side view of one of my improved thrashingmachine teeth, showing a sheet of steel secured to the end of the tooth.

Fig. 2 is a front view of the same tooth, and

Fig. 3 is an end view of the same, showing the bent sheet-steel wearing-piece.

Thrashing machine cylinders are run at a very high speed. The teeth on the cylinders, as also the fixed teeth, are subjected to a large amount of strain by the rapid succession of blows. To resist these blows the teeth have to be made of very tough iron, and their construction must be such as will insure them against breakage. on the cylinder by a shoulder, theyare inserted into tapering holes, so as to present the greatest thickness of metal on the periphery of the cylinder, from which point the thickness diminishes, while the depth or breadth of the tooth increases toward the end. Atthe outer end of the tooth and on the forward faceof the same all the blows are exerted and all the wearof the tooth comes. As this part passes only through the otherteeth, and having provided for the rigidity of the tooth to withstand the blows and retain its position, it becomes necessary to protect the teeth against the wearing action of the blows -on the face of the teeth.

In the drawings, Ais the thrashing-machine tooth, provided with the taper a, which enters the socket, and the screw a, by which it is secured.

B is the sheet-steel re-enforcement, consisting of a piece of bent sheet-steel, so as to present the double end on the forward edgeof the tooth and to resist all wear caused by the blows. The re-enforcement B is shown as forming a section of a circle the center of which is at d, and when so made it is secured by the Instead of resting them or breaking strains.

In practice iron teeth resist the strain caused by the blows, but are liable to soon wear on the ends and become useless. Steel teeth present the opposite difficulty. When the ends are hardened they will resist wear for along time; but no matter how carefully hardened the change in the structure caused by hardening will extend toward the base of the tooth, and such teeth are very liable to break and cause injury to the machine.

With my improved tooth,consistingof tough fibrousiron re'enforced by a doubled steel plate, all these difficulties are avoided. The steel plate may be hardened without affecting the iron tooth, anda tooth combining the maximum of resistance with the maximum of hardness at the wearing end is the result.

By making the re-enl'orcement of circular form, the center of the circle being on the side of the tooth, and swaging or forming the tooth so as to receive the same, the steel re-enforcemeal; will be easily retained, as the centrifugal force, as well as theforce of the blows, is taken up by the shoulder on the tooth.

I am aware that a fibrous iron thrashingmachine tooth has had its front edge faced with steel, and I do not claim such a tooth broadly.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The thrashing-machine tooth A, made of tough iron, and having its forward upper portion provided with the re-enforce B, consisting of a plate of steel folded to fit over the upper portion of the front edge and along both sides of the upper front portion of the tooth, said re-enforce being secured in place by a rivet passing through both its side portions and the portion of the tooth between them, substantially as described.

In witness whereof I have hereunto set my hand.

' LUOIUS CARRIER. Witnesses I WILLIAM L. GooP, H. J. MILLER. 

